Tom Harris, also known as The Hill Country Gardener, is a Master Gardener certified by the State of Texas, a Master Pruner certified by the San Antonio Botanical Garden, and a founder and volunteer for the Gardening Volunteers of South Texas (GVST).

Note: This is an mySA.com City Brights Blog. These blogs are not written or edited by mySA or the San Antonio Express-News. The authors are solely responsible for the content.

Yes, I know that flowers, veggies, and all plants need moisture to live, but what this means is that the soil must be moist — not sloppy wet. The reason most plants can’t grow in water is because there is very little oxygen in water. Plant roots need air and that air must be in the soil. THAT’S why we keep telling you to add more organic matter to the soil — it holds moisture and oxygen.

Also, don’t fertilize a plant every few days or you’ll kill it that way, too. Plants can only take up so much food from the soil. If there is too much food (fertilizer) in the soil, it has a very detrimental effect on the roots — it burns them. Those little, tender, white roots that do most of the work of the root system are VERY tender and easy to kill. Most of us never see these tiny roots because they are so small and tender that they break off when we pull a plant from the ground. Just take my word for it, they can do a wonderful job when the moisture and food content of the soil is right or even close to right, but if you over-do it, just a little, the plants can’t handle it and will just wilt and die.

And let me remind you again about watering in the afternoon. I know that dragging out the hose after we get home from work and watering plants that look wilted is good therapy. It just feels good to know that we’re giving our little thirsty plants a good drink of cool water. WRONG!!!!!

This is the worst time to be watering plants for several reasons. First, wilted leaves in the late afternoon don’t necessarily mean that the soil around the root system is dry. It only means that the leaves are wilted due to the hot sun that they are exposed to all day long. Plants “breath” out moisture, just like we do. This moisture comes from the moisture stored in the leaves. When the moisture is expelled out of the leaves, the leaves wilt. The plant is perfectly capable of bringing more moisture from the soil if it’s available and it will do that overnight. The next morning, the leaves will be back like they’re supposed to be; i.e., nice and flat or whatever the shape is supposed to be. So if you want to look at the leaves to determine if the plant needs water, wait until the morning to look at it. If it’s wilted in the morning, then it probably needs watering.

The best way to tell if the soil is dry, however, is to stick your finger into the soil. If it’s dry down to about the second joint on your finger, it’s dry enough to water. Then, and only then, should you be adding water.

The second reason not to water in the afternoon is that it can actually help fungus problems get started. Fungi love moisture, darkness, and warmth … all of which we have around here much of the time. If you water in the evening after work, the leaves stay wet during the evening and dark hours and the fungi LUV it when that happens. They really get to work doing their thing overnight … and about 80 percent of the problems that we have with plants around here are fungus problems; many of them caused by simply watering at the wrong time. Haven’t you ever noticed that the nurseries water in the morning? The reason is that they don’t want some fungus to wipe out their whole inventory.

This also reminds me to tell you to stop watering the grass. It still doesn’t need any supplemental water from us. There’s plenty of water in the ground. Hellooooo!!!!! We’ve had more rain this year than the last 2-3 years combined, so there’s plenty of water down there. If you’ll stop watering, you’ll find that the grass will get greener and stronger because of the sunshine. It’ll also help the grass put down deeper roots to get to the water that’s down there. It doesn’t need any more water or fertilizer, thank you very much.